Lesions of the Basal Forebrain Cholinergic System in Mice Disrupt Idiothetic Navigation

Loss of integrity of the basal forebrain cholinergic neurons is a consistent feature of Alzheimer’s disease, and measurement of basal forebrain degeneration by magnetic resonance imaging is emerging as a sensitive diagnostic marker for prodromal disease. It is also known that Alzheimer’s disease patients perform poorly on both real space and computerized cued (allothetic) or uncued (idiothetic) recall navigation tasks. Although the hippocampus is required for allothetic navigation, lesions of this region only mildly affect idiothetic navigation. Here we tested the hypothesis that the cholinergic medial septo-hippocampal circuit is important for idiothetic navigation. Basal forebrain cholinergic neurons were selectively lesioned in mice using the toxin saporin conjugated to a basal forebrain cholinergic neuronal marker, the p75 neurotrophin receptor. Control animals were able to learn and remember spatial information when tested on a modified version of the passive place avoidance test where all extramaze cues were removed, and animals had to rely on idiothetic signals. However, the exploratory behaviour of mice with cholinergic basal forebrain lesions was highly disorganized during this test. By contrast, the lesioned animals performed no differently from controls in tasks involving contextual fear conditioning and spatial working memory (Y maze), and displayed no deficits in potentially confounding behaviours such as motor performance, anxiety, or disturbed sleep/wake cycles. These data suggest that the basal forebrain cholinergic system plays a specific role in idiothetic navigation, a modality that is impaired early in Alzheimer’s disease.     

Antioxidant and Antidiabetic Properties of Extracts from Three Underutilized Food Plants of North East India

Three underutilized leafy vegetables Sarcochlamys pulcherrima (Roxb.) Gaudich (SP), Ipomoea aquatica Forssk. (IA) and Zanthoxylum rhetsa (Roxb.) DC (ZR) were extracted with different solvents viz. 95 % ethyl alcohol, methanol and hot water. The extracts were evaluated for their antioxidant potential via DPPH, ABTS and FRAP assay along with electroanalytical studies using cyclic voltammetry. The antidiabetic potential was determined by recording their α-amylase and α-glucosidase inhibitory assay. The total phenolic content (TPC), total flavonoid content (TFC) and the liquid chromatography-mass spectrometry (LC/MS) based phytochemical profiles of the extracts were also determined. All three extracts of SP exhibited significant antioxidant capacity. The antidiabetic potential of the IA and ZR extracts was found to be higher than or at par with that of standard acarbose. LC/MS studies reveal the presence of hitherto reported antioxidant and antidiabetic compounds like gamma-aminobutyric acid, cinnamic acid, caffeic acid, α-viniferin, piperlonguminine, niacin, kaempferol, etc., in the extracts.     

Epigenetic mechanisms of plant stress responses and adaptation

Epigenetics has become one of the hottest topics of research in plant functional genomics since it appears promising in deciphering and imparting stress-adaptive potential in crops and other plant species. Recently, numerous studies have provided new insights into the epigenetic control of stress adaptation. Epigenetic control of stress-induced phenotypic response of plants involves gene regulation. Growing evidence suggest that methylation of DNA in response to stress leads to the variation in phenotype. Transposon mobility, siRNA-mediated methylation and host methyltransferase activation have been implicated in this process. This review presents the current status of epigenetics of plant stress responses with a view to use this knowledge towards engineering plants for stress tolerance.     

Auxin-like activity of extract from hypertrophied tissue of <Emphasis Type="Italic">Acacia eburnea</Emphasis> infected with <Emphasis Type="Italic">Ravenelia esculenta</Emphasis>

Ravenelia esculenta Naras. and Thirum. is a rust, pathogenic to Acacia eburnea Willd. The infection leads to hypertrophy changing the morphology with bizarre shapes of plant organs. Healthy and infected tissues were subjected to extraction of IAA and indole derivatives and were estimated by spectrophotometric methods. The hypertrophy produced was presumed to be due to increase in the indole-3-acetic acid (IAA) content in the infected tissue, however, the amount of IAA in infected tissues decreased with the progression of disease. Concomitantly, the infected tissue showed the presence of a novel, slow migrating, indole derivative on TLC. Cultured shoot tips of Withania somnifera were dosed with the methanolic extract of the infected hypertrophied tissue (MEHT) (0.25, 0.5, 0.75, 1.00 and 1.25 mg/l). The stimulation in shoot growth along with profuse rooting was observed in a dose dependent manner with maximum at 1.00 and 1.25 mg/l concentration.     

Fuzzy logic feedback control for fed-batch enzymatic hydrolysis of lignocellulosic biomass

A fuzzy logic feedback control system was developed for process monitoring and feeding control in fed-batch enzymatic hydrolysis of a lignocellulosic biomass, dilute acid-pretreated corn stover. Digested glucose from hydrolysis reaction was assigned as input while doser feeding time and speed of pretreated biomass were responses from fuzzy logic control system. Membership functions for these three variables and rule-base were created based on batch hydrolysis data. The system response was first tested in LabVIEW environment then the performance was evaluated through real-time hydrolysis reaction. The feeding operations were determined timely by fuzzy logic control system and efficient responses were shown to plateau phases during hydrolysis. Feeding of proper amount of cellulose and maintaining solids content was well balanced. Fuzzy logic proved to be a robust and effective online feeding control tool for fed-batch enzymatic hydrolysis.     

An improved Agrobacterium-mediated transformation of recalcitrant indica rice (Oryza sativa L.) cultivars

Agrobacterium-mediated transformation of indica rice varieties has been quite difficult as these are recalcitrant to in vitro responses. In the present study, we established a high-efficiency Agrobacterium tumefaciens-mediated transformation system of rice (Oryza sativa L. ssp. indica) cv. IR-64, Lalat, and IET-4786. Agrobacterium strain EHA-101 harboring binary vector pIG121-Hm, containing a gene encoding for β-glucuronidase (GUS) and hygromycin resistance, was used in the transformation experiments. Manipulation of different concentrations of acetosyringone, days of co-culture period, bacterial suspension of different optical densities (ODs), and the concentrations of l-cysteine in liquid followed by solid co-culture medium was done for establishing the protocol. Among the different co-culture periods, 5 days of co-culture with bacterial cells (OD_600 nm?=?0.5–0.8) promoted the highest frequency of transformation (83.04 %) in medium containing l-cysteine (400 mg l^?1). Putative transformed plants were analyzed for the presence of a transgene through genomic PCR and GUS histochemical analyses. Our results also suggest that different cultural conditions and the addition of l-cysteine in the co-culture medium improve the Agrobacterium-mediated transformation frequencies from an average of 12.82 % to 33.33 % in different indica rice cultivars.     

Synthesis and Evaluation of Anticonvulsant Activity of Some Schiff Bases of 7‐Amino‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one

A variety of 1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one azomethines and 1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one benzamide were prepared, characterized and evaluated for the anticonvulsant activity in the rat using picrotoxin‐induced seizure model. The prepared 1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one azomethine derivatives emerged potentially anticonvulsant molecular scaffolds exemplified by compounds, 7‐{(E)‐[(4‐nitrophenyl)methylidene]amino}‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one, 7‐[(E)‐{[4‐(dimethylamino)phenyl]methylidene}amino]‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one, 7‐{(E)‐[(4‐bromo‐2,6‐difluorophenyl)methylidene]amino}‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one and 7‐[(E)‐{[3‐(4‐fluorophenyl)‐1‐phenyl‐1H‐pyrazol‐4‐yl]methylidene}amino]‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one. All these four compounds have shown substantial decrease in the wet dog shake numbers and grade of convulsions with respect to the standard drug diazepam. The most active compound, 7‐[(E)‐{[4‐(dimethylamino)phenyl]methylidene}amino]‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one, exhibited 74 % protection against convulsion which was higher than the standard drug diazepam. Furthermore, to identify the binding mode of the interaction amongst the target analogs and binding site of the benzodiazepine receptor, molecular docking study and molecular dynamic simulation were carried out. Additionally, in silico pharmacokinetic and toxicity predictions of target compounds were carried out using AdmetSAR tool. Results of ADMET studies suggest that the pharmacokinetic parameters of all the target compounds were within the acceptable range to become a potential drug candidate as antiepileptic agents.     

Eco-holobiont: A new concept to identify drivers of host-associated microorganisms

Host microbiomes play a critical role in host fitness and health. Whilst the current 'holobiont' concept framework has greatly expanded eco-evolutionary and functional understanding of host-microbiome interactions, the important role of biotic interactions and microbial loop (compositional linkage between soil, plant and animal) in shaping host-microbiome are poorly understood. We proposed an 'eco-holobiont' concept to fill the knowledge gap.     

Molecular profiling in relation to drought tolerance in advance breeding lines of rice using microsatellite markers

Using agro-morphological characters and microsatellite markers, advance breeding lines of rice were discriminated for their ability to tolerate drought stress at reproductive stage. Experimental materials consisting of 17 advance breeding lines and a check were evaluated in randomized block design with three replications under irrigated condition and drought condition created under rainout shelter during three consecutive years. An analysis of variance revealed significant differences among the genotypes for all the ten agro-morphological characters evaluated under both the conditions across the years. Principal component analysis showed the relative importance of root length, number of tillers per plant, number of grains per panicle, harvest index and grain yield per plant among agro-morphological characters and stress tolerance level, stress susceptibility index, stress tolerance index and drought tolerance efficiency among drought tolerance indices as the important classification variables. Relative mean performance in respect of grain yield as well as drought tolerance indices reflected remarkably greater degree of drought tolerance in 11 advance breeding lines and the check, discriminating them from remaining entries under evaluation. Utilizing a panel of 32 microsatellite primers, selective amplification of targeted genomic regions revealed that the primers RM 72, RM 163, RM 212, RM 225, RM 231, RM 302, RM 327, RM 518, RM 521, RM 555, RM 1349, RM 3549 and RM 5443 were highly informative with greater gene diversity and discrimination ability. Hierarchical cluster analysis based on molecular profiles discriminated the entries into five genotypic groups and drought tolerant entries were accommodated into three distinct groups with remarkably greater efficiency (85.7%). Principal coordinate analysis based two dimensional plots of microsatellites dependent genetic profiles displayed a very close correspondence with the genotypic clustering pattern revealed from a perusal of dendrogram. Sequential exclusion of primers in cluster analysis led to identification of RM 212, RM 231, RM 324, RM 431, RM 521, RM 3549 and RM 6374 as the most useful primers for discrimination of drought tolerant and susceptible lines of rice. Molecular profiling based on these markers can be utilized as efficient tools for discrimination and identification of drought tolerant lines.